Apparatus for orienting the structure of synthetic yarn



May 25, 1965 M. s. KANBAR 3,134,320

APPARATUS FOR ORIENTING THE STRUCTURE OF SYNTHETIC YARN Filed April 29, 1963 INVENTOR.

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United States Patent 3,184,820 APPARATUS FOR QRHENTHNG THE STRUCTURE 0F SYNTHETIC YARN Maurice S. Kanbar, 1115 E. th St, New York, FLY. Filed Apr. 29, was, Ser. No. 276,279 6 Claims. (Ci. 28-71(3) My invention relates generally to oriented synthetic yarn, and more particularly to apparatus for stretching undrawn yarn to produce an oriented yarn which is fed directly into a processing machine adapted to texturize, knit, weave, spin or otherwise process the yarn.

The present invention is applicable to polyester, acrylic, polyamide or other known types of synthetic fiber or yarn whose strength and other physical characteristics are enhanced by stretching the fiber. Stretching acts not only to increase the orientation of the fiber, but also to reduce its denier. For reasons of simplicity, the invention will be described in connection with polyamide fibers, known commercially in the United States as nylon. It is to be understood, however, that the principles underlying the invention are applicable to the various types of stretched synthetic fibers and yarns, whether mono-filament or multi-filament.

In the manufacture of nylon fiber, two distinct processes are ordinarily involved, spinning and drawing. In spinning, nylon chips or flakes are melted under an inert atmosphere, the molten nylon being extruded through a spinneret to form filaments which are then cooled and solidified, the filaments being wound on cylinders or packages. In drawing, the melt spun filament is irreversibly stretched to orient its molecular structure and thereby increase the strength and recoverable extensibility of the fiber. Thus in the conventional manufacturing process, the undrawn filament must be first wound on a tube,

of products produced from nylon. Inasmuch as one important advantage of the present invention lies in a reduction in material costs of the finished product without any loss of quality, a brief review of the current uses of nylon is in order.

Nylon is used extensively in textiles and in the industrial field. Its first major use was in ladies hosiery where it has largely replaced silk. It is now widely employed in tricot knitting, it the weaving industry, and in the making Nylon is also used for texturized yarns made by false twist, crimping or looping techniques which serve to impart a bulkier hand to the yarn or to improve its elastic properties. Among the many industrial applications for nylon are industrial filters and nylon cords and fabrics in the construction of pneumatic tires. When blended with cotton, rayon or other fibers, an improvement in abrasion is obtained. Nylon staple is also used in carpets, either alone or in mixtures with wool or cotton.

In view of the foregoing, it is the main object of this invention to provide an attachment for a processing machine which serves to stretch and orient an undrawn fiber before it is fed into the machine, whereby the machine may be operated with a low-cost undrawn fiber or yarn.

By processing machine, as used herein, is meant any mechanism or system currently employed in the textile or industrial field for texturizing a fiber or yarn orfor fabricating it into a stocking, a fabric, or any other product formed by knitting, weaving, braiding or otherwise processing an oriented synthetic fiber or yarn.

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More particularly, it is an object of this invention to provide an auxiliary device or attachment which serves to stretch fiber or yarn at a relatively slow speed determined by the operating speed of the processing machine into which the stretched material is fed, whereby the strength of the material is greater than that obtained from commercial drawing operations.

Where the yarn is stretched in the course of the manufacturing process in accordance with standard practice, such stretching, which involves unwinding the undrawn yarn and thereafter winding the stretched yarn, is ordinarily carried out at very high speeds to reduce processing costs. The break point of the yarn is determined not only by the degree of elongation to which the yarn is subjected, but also by the rate at which drawing takes place. Hence to avoid rupture, the yarn in high-speed drawing cannot be stretched to the same degree as would be possible at lower speeds.

A salient advantage of the present invention is that since the drawing speed is determined by the processing machine, which in most instances such as in texturizing and knitting, operates at a relatively slow rate as compared to drawing operations in the yarn-manufacturing process, it becomes possible safely to stretch the yarn to a greater degree. In this way, tensile strength values are obtained beyond those normally found in pre-oriented yarns of the type which are commercially available. Moreover the possibility of broken filaments in a multifilament yarn is reduced when drawing at low speeds. A substantial percentage of commercially available predrawn yarn is of inferior grade by reason of such broken filaments.

Also an object of the invention is to provide an attachment of the above-descriped type wherein the operation of the drawing rolls is governed by the processing machine without any mechanical linkage therebetween to maintain a flow of yarn as required, and to arrest the operation of the attachment when necessary, thereby effectively maintaining synchronism between the attachment and the processing machine.

Still another object of the invention is to provide a yarn-stretching attachment of simple, efiicient and reliable design which may be readily coupled to any existing yarnprocessing machine to render it operable with low-cost undrawn yarn.

Briefly stated, these objects are accomplished by an attachment wherein undrawn yarn is conveyed by a feed roll at a uniform rate from a melt-spun yarn package to a draw roll whose peripheral speed is greater than the feed, thereby stretching the yarn to an extent determined by the relative speed of the rolls, the stretched yarn from the draw rolls being conveyed through a sensing device into the processing machine, the sensing device serving to control the rotation of the draw and feed rolls in response to the action of the processing machine, whereby oriented yarn is supplied in accordance with machine demand.

For a better understanding of the invention, as well as other objects and further features thereof, reference is made to the following detailed description to be read in connection with the accompanying drawing, which schematically shows an attachment in accordance with the invention, operating in conjunction with a processing machine.

Referring now to the drawing, there is shown an attachment in accordance with the invention, generally designated by numeral 19, for stretching undrawn yarn,'such as nylon, and for feeding the oriented yarn into a processing machine, which by way of example is a circular knitting machine 11, for making ladies hosiery.

The undrawn yarn is wound on a supply package 12, the yarn in the case of nylon, being made by any known operation to feed yarn to the machine.

and is then, after being water or air cooled, wound on a tube. The undrawn yarn 13 taken -from the supply package is conducted by suitable guides 14 and 15 into feed rolls'16 and 17. From the feed rolls the yarn is looped over a drawn pin 18, and then wrapped several timesaround adraw roll 19, the wraps being kept apart by a separator roll 20. From the draw roll 19, the stretched yarn goesthrough a guide 21 and passes by a sensor 22,.

the yarn then going out of outlet 23 into the cylindrical needle bed of the knitting machine 11.

The draw roll 19 is driven through a clutch 24 by means of an electric motor 25 whose speed is adjusted from a control box 26 including a variable resistance or other known means to vary the voltage applied to the motor.

control. 7 The draw roll 19 is mechanically coupled by a gear reduction train to the feed rolls 1647 to provide the desired speed ratio between the feed and draw rolls, whereby the yarn maybe stretched to 3 to 4- or times its original length, depending on the nature of the polymer. Thus in the case of nylon, the stretch is usually not over 4.5, whereas for polystyrene it may go as high as 7 or 8 times ,the original length.

Thus the undrawn yarn is unwound at a uniform rate from the melt-spun yarn package 12 to the draw roll 19, the point of drawing being between the draw pin 13 and the draw roll 19. A number of wraps around the draw roll are requiredto prevent yarn slippage, the axis of the separator roll being inclined slightly relative to the draw roll andserving to keep the Wraps apart. The draw ratio is that between the peripheral speed of the draw and feed rolls. If desired, heat may be supplied to the drawing point to efiect hot drawing, thereby lowering the drawing load more than the breaking load to enable a greater draw spinning process, such as grid spinning or band spinning 5 wherein molten nylon is extruded through a spinneret vention, to use an vunstretched low-cost starting yarn.

In practice a universally woundmotor may be used in conjunction with a variac or variable transformer ratio to be achieved. Also, the yarn leaving the draw roll may be twisted by conventional ring twister means;

Sensor 22 serves to indicate whether the knitting ma-. chine 11 or other processing device requires yarn, in which event the sensor serves to maintain the attachment in For example, in the case of a knitting machine for stockings wherein the operation stops and starts when switching from the body to the welt, to prevent yarn overfeed it is necessary that the attachment be halted when the knitting operation stops and resumed concurrently with theresumption of knitting.

The sensor in its simplest form may be a microswitch having an actuator arm which engages the yarn, the arm being so biased that when the yarn is under tension as a result of machine demand, the switch. is closed. The switch acts to activate the clutch 24, which may be electromagnetically operated or of the fluid type to effect engagement between the drive motor 25 and the feed and draw rolls. When, however, the yarn tension is relaxed, which occurs when knitting is stopped, the switch opens to disengage the clutch. In practice, other forms of mechanical, optical 'or electrical sensors may be used to activate and deactivate the attachment in response to the processing machine demand. It is also possible to dis pense with the clutch and turn the motor on and oh? under the control of the sensor. i

In operation, the speed of the motor is adjustedso that yarn is supplied to the processing machine in accordance with the demand or slightly faster. Should the rate of demand fluctuate, with an overfeed of yarn, the sensor will act to cut oft the attachment to take up the overfeed.

The attachment may take the form of a self-contained and housed unit including the motor and control means thereof, whereby the unit may be readily installed on an existing processing machine to adjust it for use with undrawn yarn. Or the attachment may be integrated with the processing machine and driven by a common motor.

To facilitate drawing and to reduce static electric charges, the undrawn yarn is preferablyexposed to steam or high humidity in order to raise its moisture content. This may be accomplished in several ways. The packages of undrawn yarn may, for instance, be stored in a room having high humidity, for several days before use.

'yarn in accordance withthe invention,it will be appre ciated that many changes and modifications may be made therein without,- however, departing from .the essential spirit of the invention as defined in the annexed claims.

What is claimed is: I. An attachment for a machine adapted to process an oriented synthetic yarn to render said machine operable with undrawn yarn, the yarn demand of said machine being intermittent, said attachment comprisinga supply package of undrawn synthetic yarn, feed rolls, draw rolls, motor means'to drivesaid draw rolls ata high speed relative to said feed rolls, means to guide yarn from said package successively through said feed rolls and draw rolls to effect stretching thereof to an extent determined by the ratio of speed therebetween, means to guide said stretched yarn from said draw rollsto said machine to process same, and control means to discontinue thedrive of said motor means when-the yarn demand of said machine is inter rupted and to continue said drive when yarn demand is resumed.

2. An attachment as set forth in claim 1, wherein'said yarn is nylon. I

3. Anattachment as set forth in claim 1, wherein said ratio is about 3.5 to 1.

4. An attachment as set forth in claim 1 wherein, said control means includesmeans sensing the yarn as it is led into said machine to indicate the machine demand therefor, and means responsive to said sensing means to control said motor means'to accommodate the supply of said yarn to said demand.

5. An attachment for a machine'adapted to process a stretched synthetic yarn to render said machine operable with unstretched yarn, said attachment comprising feed rolls and draw rolls, motor means for concurrently driving said rolis at different speeds having a predetermined speed ratio, means guiding unstretched yarn successively through said feed rolls and said draw rolls to eiiect stretching thereof to a degree determined by said ratio, means to guidesaid stretched yarn into said machine, a sensor engaging said yarn issuing from said draw rolls and responsive to the tension exerted thereon by said machine The attachment is also useable with bulked or textured yarn machines for producinlg yarns marketed under such trademarks as Taslan, Flufion,-Helanca, Supersoft and Chadalon.

In the Flufion machine, stretched yarns are produced (References on following page) References Cited by the Examiner UNITED STATES PATENTS Taylor 28-713 X Slovin 28-12 Lassiter 66-132 Evans 28-713 X Olson 28-72 6 Sinclair 66-132 Masurel et a1. 139-1 Breen et a1. 28-72 Brandt 66-9 Strub 66-125 Biggers 66-125 MERVIN STEIN, Primary Examiner. 

1. AN ATTACHMENT FOR A MACHINE ADAPTED TO PROCESS AN ORIENTED SYNTHETIC YARN TO RENDER SAID MACHINE OPERABLE WITH UNDRAWN YARN, THE YARN DEMAND OF SAID MACHINE BEING INTERMITTENT, SAID ATTACHMENT COMPRISING A SUPPLY PACKAGE OF UNDRAWN SYNEHETIC YARN, FEED ROLLS, DRAW ROLLS. MOTOR MEANS TO DRIVE SAID DRAW ROLLS AT A HIGH SPEED RELATIVE TO SAID FEED ROLLS, MEANS TO GUIDE YARN FROM SAID PACKAGE SUCCESSIVELY THROUGH SAID FEED ROLLS AND DRAW ROLLS TO EFFECT STRETCHING THEREOF TO AN EXTENT DETERMINED BY THE RATIO OF SPEED THEREBETWEEN, MEANS TO GUIDE SAID STRETCHED 